Method of forming printing surfaces



P. J. WOOD.

METHOD OF FORMING PRINTING SURFACES. APPLICATION FILED AUG-l9. 1921.

EAfiGAQQ, I Patented Nov. 21,1922.

WIT/V588 INVENTOR' 1 f who} S-W cEL. Y a w 9 P ATTORNEY.

Patented Nov. 21, 1922.

p esent it bbwr ATERIS N l iE' E ivr-E'rfion or-ro'a N'G 9 1m surtraons.

,Applicatidngfil'ed August: 19,!1921. Serial No, 493,544.

used in printing, either directly as the printing surface or in'thegforming oft-he print ing surface by -the etchin process, whereby graded-toneeffects, as :clbuded for mottled effects, splotches :or stripes, may be brought out in the printing, the same -.consist1ng broadly inuforcinginto such surface the acting-l faces of an assembly of gravers while maintaining said assembly in convergent relation to said surface, and I have set forth that this maintaining of the gravers-assembly in convergent relation to the surface to be treated may be accomplished by supportingthe same at a higher elevation than said surface, or it may be accomplished by making the relative forms of the the surface of the graversassembly and the surface to be treated such that one is convex and they do not conform, claiming in said application the former of these two and reserving for this application the latter, which I accordingly describe and claim herein as follows, referring, first, to the accompanying drawing wherein- Figure 1 shows a tampon used in perform.- ing my method;

' Figure 2 is a sectional view on a magnified scale of a fragment of the same and the surface to be treated at the moment of forcing the tampon into said surface; and

Figure 3 shows the effect produced in the surface treated by application of the tampon thereto. Y

Z is a tampon, pad or other body whose form is normally convex and is here shown as having a fabric exterior, the fabric being of such coarseness that the bends Z of its threads will make more or less distinct incisions in a yieldable surface if the fabric be forced thereinto, such bends in the present instance being taken as the gravers. A is the surface to be treated, being here a varnish coating 1 on, a ,harder Usurface g copper), which may be the surface-of a plate, or. cylinder. ;Whether surface A be taken as a plane or cylinder (in which latter .case Fig. 2 would show a longitudinal section) 'it'and -the su'rface formed; by vthe acting faces of the assembly of gravers -Z .do not conform; that is to say, these surfaces are so formed that one (here'the surface ofthe gravers-assembly) is-flnormally convex ,andif they be brought together only a limited part of each can-initially contact with the other.

. If, then, they be brought together with slfifhcient force so I that the, gravers incise the surface I A the incisions will \be graded, as atimati the right-ofwFigsQ (see also. the niarginsof the SPlOtCllQSrShOWIl in Fig. 3),

because of the (convergence --that exists .be-

tween the two surfaces. This is primarily a matter of the relative forms of the two surfaces, to Wit, one of them (the surface of the gravers-assembly in the present example) being convex and the other not conforming thereto; the effect produced will be modified by other circumstances, such as whether or not the tampon is yielding. the degree of force used and how it is applied,- as by a blow or by pressure, and whether or not the gravers, after entering the surface A, encountered resistance such as that afforded the harder material 9.

In actual practice, however, I have formed the tampon of a wad of indiscriminately massed fabric of suitable coarseness or of a wad of any other appropriate material covered with fabric of suitable coarseness so that it will be yieldable in nature. It may form a single convexity, or a plurality of them as actually shown in the drawing. It is wetted with turpentine or some other solvent ofthe surface A (the only essential being that said surface shall be yieldable to the gravers Z formed by the fabric of the tampon) andthen pressed against said surface so that the gravers incise the same. The result is that at the margin of the spot or place where the pressure is applied the incisions will be graded, increasing in size vexities so that there will be graded incisions left around the spot or place where each such convexity leaves its impression.

When the tampon is formed of yielding material one advantageous result is that different applications thereof to different places on the surface to be treated will produce divers effects, that is, impresses left by the tampon will have different configurations and different tone-effects, which it is one of the particular objects 'of' my invention to produce.

It will be understood that in the example herein shown thesurface A is taken as the coating of a body 9 which. is to form the actual printing surface and that after such coating or surface A has been treated in the way explained it will have applied thereto a suitable acid or inordant which will act to etch the surface of the body 9 where the incisions have exposed it, whereupon the coating will be removed. 7

Howeven-iny invention is not limitedto the presence of any surface back of the surface (A) being treated and acting to modify the action of the gravers, as the surface 9 actually does in the example herein "set forthyto wit, by limiting the depth of the incisions and so, by causing the yielding gravers to spread or expand, increasing more or less the area of each incision.

1 arsena Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In the art'of printing, the method of producing the herein-described graded incisions in the surface to be treated which consists in formingsaid surface and the surface formed by the acting faces of the gravers of a gravers-assembly so that one will be normally convex and when they are brought together only a limited part of each can initially contact with the other and in then forcing said surface of thegr'aversassembly against the surface to'be treated so that the acting faces of the gravel-s will enter the latter. i

2. Intheja'rt of printing, the method of producing the herein-described graded incisions in the surface to' be treated which consists in forming said surface and the surface formed by the acting faces'of the graversof a yielding gravers-assembly so 

